Den-Associated Behavior of Octopus rubescens Revealed by a Motion-Activated Camera Trap System

Area of Science:

• Marine Biology
• Behavioral Ecology
• Invertebrate Zoology

Background:

• Octopus dens are vital for shallow-water species.
• Den usage dynamics are understudied, especially for Octopus rubescens in their natural habitat.
• Previous research has not explored Octopus rubescens denning behavior in situ.

Purpose of the Study:

• To investigate the denning behavior of Octopus rubescens in their natural environment.
• To utilize underwater camera traps for observing octopus behavior and interactions.
• To understand the ecological role of Octopus rubescens dens.

Main Methods:

• Four motion-activated underwater camera traps were deployed to monitor octopus dens.
• Octopus rubescens individuals were tagged with visible implant elastomer tags for identification.
• Continuous monitoring of tagged octopuses in bottle dens was conducted over a month.

Main Results:

• Octopus rubescens exhibit primarily diurnal activity patterns.
• Frequent interactions among conspecifics (other octopuses) were observed.
• The presence of octopuses influenced the visitation patterns of other marine species, such as rockfish, red rock crabs, and kelp greenling.

Conclusions:

• Motion-activated camera traps are effective tools for studying the behavior of mobile nearshore organisms.
• Octopus rubescens denning behavior and ecological interactions can be successfully monitored in situ.
• The study highlights the importance of octopus dens in structuring nearshore communities.